1. Field of the Invention
The present invention relates to a power working machine equipped with an internal combustion engine having a spark plug. The present invention also concerns a spark plug guard for protecting the spark plug.
2. Description of the Related Art
Some portable working machines such as brush cutters and hedge trimmers are equipped with an internal combustion engine, such as a small air-cooled two-stroke cycle gasoline engine, as a prime mover for driving a cutting blade (a working member). The internal combustion engine has a spark plug at the head of a cylinder constituting the engine body. The terminal of the spark plug projecting outward from the cylinder head is covered with a detachable plug cap, to which an ignition high-tension lead is connected, for protection.
In order to protect the spark plug perfectly, it is preferable to provide a spark plug guard for covering above the plug cap. This is for the purpose of preventing damage to the spark plug by the contact of the plug cap with articles during transportation of the portable working machine by track or the like, during depositing in storage, or during replacement of the cutting blade with the internal combustion engine placed upside down on the ground.
However, if the spark plug guard is secured to the engine body with screws and so on, troublesome detachment work of the spark plug guard is required during maintenance of the spark plug, thus resulting in a decrease in workability.
Also, if a part designed specifically for protection of the spark plug is mounted to the engine body, the machine increases in weight correspondingly, thus going against the demand for compact and lightweight portable working machines and causing an increase in cost.